4 -1/4" stroke. Stock replacement for 80" (1340cc) fuel injected Evolution Big Twin models. Used with stock or stock weight pistons like S&S 536052 series. Re-balancing is not required. Note: These flywheels are notched and therefore compatible with fuel injected models. Note: For 90-99 models; with stock 3-piece flywheels with non-removable sprocket & pinion shafts; it is required to use pre-90 pinion shaft parts when converting to any (early) 5-piece flywheels assembly. S&S offers these parts as 904148; a ''90-99 Pinion Shaft Conversion Kit''. Note: In any and all applications the technician must be able to judge components for their suitability in combination with the other engine components; prior to installation. It is of importance that a knowledgeable mechanic will install & make adjustments as required.